The present invention generally concerns an assistance system for a driver of a vehicle, and more particularly a system for reminding the driver of the presence of at least some specific traffic signs on the way.
Today, drivers are already helped by automatic systems among which localization systems (GPS).
However, although a GPS system can be updated in view of the modifications of the roads, it does not include exhaustive information about the traffic signalization. The main reason is that traffic signalization may change without notice to cartographic organisms. Also, a road worker can modify the traffic signalization.
It would be useful to signal to a driver at least some important traffic signs. This could avoid accidents due to driver""s negligence.
The present invention aims at providing such an automatic traffic sign recognition system on a vehicle to remind a driver of the presence of some traffic signs on the road.
Another purpose of the invention is to provide a system that recognizes traffic signs even if some of them are illegible.
There is a technical problem in detecting the presence of traffic signs on the road and, more particularly, in distinguishing two successive traffic signs present on the same road. Indeed, all the traffic signs do not have the same size and a larger traffic sign seen by the driver is not necessarily the first traffic sign encountered along his way.
To attain these purposes and others, the present invention provides a system for reminding a driver of a vehicle the presence of a particular traffic sign on the way comprising:
an imaging unit attached to the vehicle and directed towards the road in the front of the vehicle;
an automatic recognition unit of pre-registered traffic signs contained in a library; and
a sound and/or visual indicator of an identified traffic sign present on the road ahead of the vehicle.
According to the present invention, the system takes periodical pictures of the road ahead of the vehicle. The periodicity of the pictures preferably depends upon the speed of the vehicle.
In each country, the shapes of the traffic signs are standardized and various symbols can be marked on each sign. For example, in Europe, only the xe2x80x9cstopxe2x80x9d sign has an octagonal shape, and only the xe2x80x9cgive wayxe2x80x9d sign has the shape of an inverted triangle.
So, each picture is analyzed in a shape recognition processor to detect the eventual presence of shapes looking like traffic sign shapes pre-registered in a database. This database or library may contain not only the shapes of the traffic signs, but also the symbols inside the traffic signs. So, the system is also able to distinguish different traffic signs having the same shape.
When the system detects the presence of traffic signs ahead of the vehicle, a sound and/or visual indicator provided inside the vehicle is actuated to remind the driver of the presence of traffic signs on the road. Then, the attention of the driver is stimulated.
According to an embodiment of the present invention, the system registers at least two successive images of the road to be able to distinguish the first coming traffic sign between two successive signs detected in a picture. For this purpose, the system compares the variation of the rectangular coordinates of a reference point of the sign picture in two successive images to determine the rank between two such analyzed signs. This can also be used to evaluate the distance separating the vehicle from the next traffic sign by combining the rectangular coordinate evaluation with the speed of the vehicle.